Cómo obtener comentarios de columna de SQL

SELECT
    COLUMN_COMMENT
FROM
    INFORMATION_SCHEMA.COLUMNS
WHERE
    TABLE_SCHEMA = 'db-name' AND
    TABLE_NAME = 'table-name' AND
    COLUMN_NAME = 'column-name'

http://dev.mysql.com/doc/refman /5.0/es/columnas-tabla.html